Good Point- quick scan of laymans documentation located at http://en.wikipedia.org/wiki/Transmission_Control_Protocol SYN or SYNchronization request happens when an agent attempts To establish a connection, TCP uses a three-way handshake. Before a client attempts to connect with a server, the server must first bind to a port to open it up for connections: this is called a passive open. Once the passive open is established, a client may initiate an active open. To establish a connection, the three-way (or 3-step) handshake occurs: The active open is performed by the client sending a SYN to the server.In response, the server replies with a SYN-ACK.Finally the client sends an ACK back to the server.To quote the doc RST (Reset connection) happens when:
A connection can be "half-open", in which case one side has terminated its end, but the other has not. The side that has terminated can no longer send any data into or receive any data from the connection, but the other side can (but generally if it tries, this should result in no acknowledgment and therefore a timeout, or else result in a positive RST, and either way thereby the destruction of the half-open socket). i'm reaching back 20 years when I took the comm class where the most current Text was Tannenbaum's Computer Networks ..I'm sure there is more current and uptodate info available Anyone? Thanks, Martin ______________________________________________ Disclaimer and confidentiality note Everything in this e-mail and any attachments relates to the official business of Sender. This transmission is of a confidential nature and Sender does not endorse distribution to any party other than intended recipient. Sender does not necessarily endorse content contained within this transmission. > To: users@tomcat.apache.org > Subject: RE: Where to look for "connection refused" errors in Tomcat6.0.18 ? > From: [EMAIL PROTECTED] > Date: Sat, 18 Oct 2008 15:54:38 +0530 > > Thanks Peter for your answer . you said : > > You *can never* see these errors in Tomcat, because Tomcat is never > > aware that the connection was received. The operating system's > > TCP/IP stack has received the incoming SYN, tried to queue the > > connection request on Tomcat's accept queue, failed, and simply > > sends a RST to close the connection. > > What do these jargons SYN and RST actually mean ? I do not know TCP IP > details . > > Regards, > > Subhrajyoti > Mobile: +919830079545 > Mail: [EMAIL PROTECTED] > Web: www.labware.com > > LabWare LIMS Solutions - Results Count > > Peter Crowther <[EMAIL PROTECTED]> wrote on 10/17/2008 06:45:13 > PM: > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > > > "If still more simultaneous requests are received, they are > > > stacked up inside the server socket created by the Connector, > > > up to the > > > configured maximum (the value of the acceptCount attribute. > > > Any further > > > simultaneous requests will receive "connection refused" errors, until > > > resources are available to process them. " So where can we > > > expect to see those errors in Tomcat? > > > > You *can never* see these errors in Tomcat, because Tomcat is never > > aware that the connection was received. The operating system's > > TCP/IP stack has received the incoming SYN, tried to queue the > > connection request on Tomcat's accept queue, failed, and simply > > sends a RST to close the connection. > > > > You *might* be able to monitor the total number of connection > > refusals at the OS level. Netstat on Windows will give you this, > > for example, though it combines refusals due to load and refusals > > due to no port being configured to accept a connection. > > > > - Peter > > > > --------------------------------------------------------------------- > > To start a new topic, e-mail: users@tomcat.apache.org > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > _________________________________________________________________ Stay organized with simple drag and drop from Windows Live Hotmail. http://windowslive.com/Explore/hotmail?ocid=TXT_TAGLM_WL_hotmail_102008
